Assessing Cognitive Features of Dementia Progression for Different Dementia Levels using Feature Selection

Abstract

Purpose Dementia is a condition with symptoms of memory decline, cognitive impairment, and difficulties in language and problem-solving, among others. Early screening of dementia conditions such as Alzheimer’s disease (AD) is fundamental for quick intervention, and disease management. Currently used neuropsychological assessments are either time-consuming, invasive require scarce resources, and often not cost effective. Therefore, identifying cognitive features for different dementia sub-groups during the condition’s progression is crucial. This study uses a cost-effective data driven approach to determine whether neuropsychological items change from one stage of dementia to another.Methods Using real cases and controls from the Alzheimer’s Disease Neuroimaging Initiative data repository (ADNI) who undertook the Alzheimer’s Disease Assessment Scale-Cognitive 13 (ADAS-Cog), we conducted a feature-feature assessment to derive influential cognitive features for specific dementia groups from baseline diagnosis up to 36 months.Results The results reveal non-overlapping features (‘command’, ‘naming of objects’, and ‘ideational praxis’) from participants who had a baseline diagnosis of Cognitively Normal (CN) and progressed to AD. In addition, overlapping of cognitive elements was observed for Mild Cognitive Impairment (MCI) subjects who advanced to AD.Conclusion This study revealed influential cognitive subsets that are uniquely associated with certain dementia stages. The overlapping of features in groups that remained in mild cognitive impairment or progressed to light dementia argues against separating these groups on these features. Other features (e.g., ‘spoken language’ and ‘word recognition’ in the ‘Cog-MCI-AD’ sub-group) showed much less correlation, indicating that these should be investigated further when assessing patients with MCI.